Access key for an automobile capable of performing exchanges using near-field communication

The assembly has a service right applying identifier (200) e.g. convego air mobile(RTM: sticker for contactless payment), forming an autonomous near field identifier independently from a motor vehicle starting and/or unlocking identifier (100) such that the service right applying identifier directly communicates with a near field communication reader (300) connected with or separated from the starting and/or unlocking identifier. The service right applying identifier comprises an adhesive surface for being fixed on a support surface (102) of the starting and/or unlocking identifier.